1. Introduction to Concepts of Climate Change Impact on Livestock and Its Adaptation and Mitigation

This chapter provides an overview of the impact of climate change on livestock production and its adaptation and mitigation. Animal agriculture is the major contributor to increasing methane (CH₄) and nitrous oxide (N₂O) concentrations in Earth’s atmosphere. Generally there are two-way impacts of livestock on climate change. The first part is the livestock contribution to climate change, while the second part is concerned with livestock getting affected by climate change. Hence, improving livestock production under changing climate scenario must target both reducing greenhouse gas (GHG) emission from livestock and reducing the effect of climate change on livestock production. These efforts will optimize livestock production under the changing climate scenario. The role of livestock on climate change is primarily due to enteric CH₄ emission and those from manure management. Various GHG mitigation strategies include manipulation of rumen microbial ecosystem, plant secondary metabolites, ration balancing, alternate hydrogen sinks, manure management, and modeling to curtail GHG emission. Adapting to climate change and reducing GHG emissions may require significant changes in production technology and farming systems that could affect productivity. Many viable opportunities exist for reducing CH₄ emissions from enteric fermentation in ruminant animals and from livestock manure management facilities. To be considered viable, these emission reduction strategies must be consistent with the continued economic viability of the producer and must accommodate cultural factors that affect livestock ownership and management. The direct impacts of climate change on livestock are on its growth, milk production, reproduction, metabolic activity, and disease occurrences. The indirect impacts of climate change on livestock are in reducing water and pasture availability and other feed resources. Amelioration of environmental stress impact on livestock requires multidisciplinary approaches which emphasize animal nutrition, housing, and animal health. It is important to understand the livestock responses to the environment and analyze them, in order to design modifications of nutritional and environmental management, thereby improving animal comfort and performance.